At the same time, lawmakers on Thursday tentatively approved a bill that tightens the standards for those who are enrolled in the tree growth program so it can’t be used simply as a tax shelter.

The 40-year-old program provides landowners with a property tax abatement if they agree to adopt sustainable timber-harvesting practices on their land.

According to Mary McDonald, who is the assistant to the Georgetown Board of Selectmen, Poliquin enrolled in the program in 2004 when he applied to set aside 10 acres of his property for tree growth. By doing so, he reduced the assessed value of his property from about $1.75 million to $725,000 and saved $5,000 annually in property taxes, according to Maine’s Majority, which cited town tax records.

McDonald said Georgetown has 10 parcels in the tree growth program, but she didn’t have data available about how the program has affected revenues for the town. Part of the reason for that is that the town needs to reassess its property, she said.

News of Poliquin’s participation in the tree growth program was released on Wednesday by Maine’s Majority, a nonprofit group that has been a vocal opponent of Gov. Paul LePage’s administration.

Poliquin purchased the property at the end of a peninsula for $1.7 million in 2001 but the value increased to nearly $3 million by 2003 when he razed the building on the land and built a new house.

He asked the town of Georgetown — and later the Sagadahoc County commissioners — to lower that assessment back down below $2 million. Both times, Poliquin was denied.

“Over the years, the people of Georgetown have lost out on tens of thousands of dollars that could have been used to pay for roads, bridges and schools. All this because Bruce Poliquin doesn’t want to contribute his fair share,” said Chris Korzen of Maine’s Majority, which reported the tax findings.

Poliquin has not responded to requests for comment.

Poliquin’s deed from the Sagadahoc County Register of Deeds says “trees may be thinned only for purposes of view, and the environment shall be completely protected at all times from the excessive cutting of trees.”

The Maine Forest Service, in a 2009 report, identified the treasurer’s Georgetown property as an example of a possible misuse of that program.

In an appendix prepared by the Maine Municipal Association, the property is described as “an example of one of the most valuable residential lots in the State of Maine.” The MMA continued: “The alleged ‘current use value’ of those 10 acres under the Tree Growth program is $3,650.”

“For several reasons, including difficulty of road access and the restrictions on timber harvesting according to the state’s shoreland zoning regulations, the ability to harvest any timber on this property — even if that was the interest of the landowner — is extremely limited,” the MMA said in the report.

The Maine Forest Service responded: “The fact that some or all of the parcel is regulated by the town’s shoreland zoning ordinance has no bearing on its eligibility.” But, it said “MFS cannot divine landowner’s intent or interests from this report.”

In April 2011, the forest service sent letters to all tree growth tax program participants reminding them of the requirements, specifically that they needed to harvest trees for commercial use and adopt management plans.

“This is the public’s business. If the taxpayers of Maine are going to shoulder Mr. Poliquin’s fair share of taxes for his oceanfront mansion, then we have a right to know whether or not he’s in compliance with the very law that’s giving him this break,” Jackson said Thursday.

“I can tell you, as a logger, that if he’s ready to harvest the timber, I know many unemployed loggers ready to do the job.”

Compliance with tree growth program requirements typically falls to the local communities.

McDonald, assistant to the Georgetown selectmen, said forest management plans associated with properties in the tree growth program need to be updated every 10 years, which means selectmen will re-examine Poliquin’s in 2014. She said there has been no reaction at the local level to this week’s reports about Poliquin’s property, although she said selectmen meet again on Feb. 16.

On Thursday, members of the Legislature’s Taxation Committee passed an amended version of LD 1138, An Act To Prevent Unnecessary Expulsion of Landowners from the Maine Tree Growth Tax Law Program.

Among the added provisions was a requirement that at least one half-acre of land be excluded from parcels containing buildings, as well as at least an additional 100 feet of shoreland frontage in coastal areas. Additionally, landowners would need to sign a legal attestation that the “primary objective” of the enrolled land is to grow trees to be harvested for commercial use.

“I am pleased we were able to reach agreement on these measures,” said Rep. Seth Berry, D-Bowdoinham, the lead Democrat on the Taxation Committee. “To Democrats, the important goal was closing loopholes that are clearly being abused along the coast, shifting the tax burden unfairly to hardworking neighbors.”

The Taxation Committee postponed action on another bill, LD 1470, also related to potential loopholes in the tree growth tax credit program, until Feb. 9.

Poliquin has faced scrutiny lately after Rep. Mark Dion requested that the Attorney General’s Office investigate whether the treasurer violated the state Constitution by having a role in the private Popham Beach Club. By law, constitutional officers cannot engage in outside business or commerce while holding office.

The Maine Democratic Party also filed a complaint with the Maine Ethics Commission because Poliquin reportedly failed to disclose income related to his business holdings.

Some have speculated that the recent complains about Poliquin are political retribution for his continued criticism of MaineHousing and its executive director, Dale McCormick, who is one of the only high-ranking Democrats left in state government.